The problem with adding a bit to cover ‘hidden’ labour, is that most of the time the actual sourcing work is carried out within the ‘day’ you’ve already paid someone for.
‘I’ll be in late tomorrow/leaving early tonight, just need to pick something up’.
Ok, but getting more materials is labour, it also has extra costs like fuel, it requires sufficient cash flow etc. Seeing materials as just stuff bought from shops and labour as just time spent on site is the oversimplification that creates this mess, lol.
The problem with adding a bit to cover ‘hidden’ labour, is that most of the time the actual sourcing work is carried out within the ‘day’ you’ve already paid someone for.
‘I’ll be in late tomorrow/leaving early tonight, just need to pick something up’.